diff --git a/README.md b/README.md
index 5c2cef9..c6e9d23 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 This repository provides scripts for integrating [Kosmos
 Kredits](https://wiki.kosmos.org/Kredits) in [Hubot](http://hubot.github.com/)
 chatbots. The bot will watch for project-related things happening on the
-Internet and automatically create proposals for issuing kredits for project
+Internet and automatically create ERC721 tokens for issuing kredits for project
 contributions.
 
 ## Setup
@@ -33,7 +33,7 @@ As usual in Hubot, you can add all config as environment variables.
 The GitHub integration will watch for closed issues and merged pull requests,
 which carry a kredits label: `kredits-1`, `kredits-2`, `kredits-3` for small,
 medium and large contributions. If there are multiple people assigned, it will
-issue proposals for all of them.
+issue contribution tokens for all of them.
 
 #### Setup
 
@@ -50,7 +50,7 @@ Point a GitHub organization webhook to the following URL:
 ### MediaWiki
 
 The MediaWiki integration will periodically check for wiki page creations and
-edits. It will create kredits proposals based on amount of text added.
+edits. It will create kredits contribution tokens based on amount of text added.
 
 #### Setup
 
diff --git a/index.js b/index.js
index 54cd839..10f35e2 100644
--- a/index.js
+++ b/index.js
@@ -121,6 +121,7 @@ module.exports = async function(robot) {
       ethProvider.resetEventsBlock(nextBlock);
 
       Proposal.on('ProposalCreated', handleProposalCreated);
+      Contribution.on('ContributionAdded', handleContributionAdded);
     });
   }
 
@@ -133,6 +134,14 @@ module.exports = async function(robot) {
     });
   }
 
+  function handleContributionAdded(contributionId, contributorId, amount) {
+    Contributor.getById(contributorId).then((contributor) => {
+      Contribution.getById(contributionId).then((contribution) => {
+        robot.logger.debug(`[hubot-kredits] Contribution #${contribution.id} added (${contribution.description})`);
+      });
+    });
+  }
+
   watchContractEvents();
 
   //
diff --git a/integrations/github.js b/integrations/github.js
index 053ac64..46cfc5e 100644
--- a/integrations/github.js
+++ b/integrations/github.js
@@ -1,6 +1,10 @@
 const util = require('util');
 const fetch = require('node-fetch');
 
+function sleep(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
 module.exports = async function(robot, kredits) {
 
   function messageRoom(message) {
@@ -16,7 +20,6 @@ module.exports = async function(robot, kredits) {
   }
 
   const Contributor = kredits.Contributor;
-  const Proposal = kredits.Proposal;
   const Contribution = kredits.Contribution;
 
   function getContributorByGithubUser(username) {
@@ -32,9 +35,9 @@ module.exports = async function(robot, kredits) {
     });
   }
 
-  function createProposal(githubUser, amount, description, url, details) {
+  function createContribution(githubUser, amount, description, url, details) {
     return getContributorByGithubUser(githubUser).then(contributor => {
-      robot.logger.debug(`[hubot-kredits] Creating proposal to issue ${amount}₭S to ${githubUser} for ${url}...`);
+      robot.logger.debug(`[hubot-kredits] Creating contribution token for ${amount}₭S to ${githubUser} for ${url}...`);
 
       let contributionAttr = {
         contributorId: contributor.id,
@@ -46,9 +49,10 @@ module.exports = async function(robot, kredits) {
         kind: 'dev'
       };
 
-      return Proposal.addProposal(contributionAttr).catch(error => {
+      return Contribution.addContribution(contributionAttr).catch(error => {
         robot.logger.error(`[hubot-kredits] Error:`, error);
-        messageRoom(`I wanted to propose giving kredits to GitHub user ${githubUser} for ${url}, but I cannot find their info. Please add them as a contributor: https://kredits.kosmos.org`);
+        messageRoom(`I tried to add a contribution for ${githubUser} for ${url}, but I encountered an error when submitting the tx:`);
+        messageRoom(error.message);
       });
     });
   }
@@ -76,7 +80,7 @@ module.exports = async function(robot, kredits) {
     return amount;
   }
 
-  function handleGitHubIssueClosed(data) {
+  async function handleGitHubIssueClosed(data) {
     let recipients;
     let issue        = data.issue;
     let assignees    = issue.assignees.map(a => a.login);
@@ -87,7 +91,7 @@ module.exports = async function(robot, kredits) {
     let description = `${repoName}: ${issue.title}`;
 
     if (amount === 0) {
-      robot.logger.info('[hubot-kredits] Proposal amount from issue label is zero; ignoring');
+      robot.logger.info('[hubot-kredits] Kredits amount from issue label is zero; ignoring');
       return Promise.resolve();
     } else if (repoBlackList.includes(repoName)) {
       robot.logger.debug(`[hubot-kredits] ${repoName} is on black list; ignoring`);
@@ -100,15 +104,15 @@ module.exports = async function(robot, kredits) {
       recipients = [issue.user.login];
     }
 
-    let proposalPromises = [];
-    recipients.forEach(recipient => {
-      proposalPromises.push(
-        createProposal(recipient, amount, description, web_url, issue)
-          .catch(err => robot.logger.error(err))
-      );
-    });
+    for (const recipient of recipients) {
+      try {
+        await createContribution(recipient, amount, description, web_url, issue);
+        await sleep(60000);
+      }
+      catch (err) { robot.logger.error(err); }
+    }
 
-    return Promise.all(proposalPromises);
+    return Promise.resolve();
   }
 
   function handleGitHubPullRequestClosed(data) {
@@ -131,29 +135,28 @@ module.exports = async function(robot, kredits) {
         }
         return response.json();
       })
-      .then(issue => {
+      .then(async (issue) => {
         let amount = amountFromIssueLabels(issue);
         let repoName = pull_request.base.repo.full_name;
         let description = `${repoName}: ${pull_request.title}`;
 
         if (amount === 0) {
-          robot.logger.info('[hubot-kredits] Proposal amount from issue label is zero; ignoring');
+          robot.logger.info('[hubot-kredits] Kredits amount from issue label is zero; ignoring');
           return Promise.resolve();
         } else if (repoBlackList.includes(repoName)) {
           robot.logger.debug(`[hubot-kredits] ${repoName} is on black list; ignoring`);
           return Promise.resolve();
         }
 
-        let proposalPromises = [];
-        recipients.forEach(recipient => {
-          robot.logger.debug(`[hubot-kredits] Creating proposal for ${recipient}...`);
-          proposalPromises.push(
-            createProposal(recipient, amount, description, web_url, pull_request)
-              .catch(err => robot.logger.error(err))
-          );
-        });
+        for (const recipient of recipients) {
+          try {
+            await createContribution(recipient, amount, description, web_url, pull_request);
+            await sleep(60000);
+          }
+          catch (err) { robot.logger.error(err); }
+        }
 
-        return Promise.all(proposalPromises);
+        return Promise.resolve();
       });
   }
 
@@ -167,10 +170,12 @@ module.exports = async function(robot, kredits) {
     robot.logger.info(`Received GitHub hook. Event: ${evt}, action: ${data.action}`);
 
     if (evt === 'pull_request' && data.action === 'closed') {
-      handleGitHubPullRequestClosed(data).then(() => res.send(200));
+      handleGitHubPullRequestClosed(data);
+      res.send(200);
     }
     else if (evt === 'issues' && data.action === 'closed') {
-      handleGitHubIssueClosed(data).then(() => res.send(200));
+      handleGitHubIssueClosed(data);
+      res.send(200);
     } else {
       res.send(200);
     }
diff --git a/integrations/mediawiki.js b/integrations/mediawiki.js
index 8acd394..b814120 100644
--- a/integrations/mediawiki.js
+++ b/integrations/mediawiki.js
@@ -4,6 +4,10 @@ const fetch = require('node-fetch');
 const groupArray = require('group-array');
 const cron = require('node-cron');
 
+function sleep(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
 module.exports = async function(robot, kredits) {
 
   function messageRoom(message) {
@@ -13,7 +17,6 @@ module.exports = async function(robot, kredits) {
   robot.logger.debug('[hubot-kredits] Loading MediaWiki integration...')
 
   const Contributor = kredits.Contributor;
-  const Proposal = kredits.Proposal;
   const Contribution = kredits.Contribution;
 
   const wikiURL = process.env.KREDITS_MEDIAWIKI_URL;
@@ -30,9 +33,9 @@ module.exports = async function(robot, kredits) {
     });
   }
 
-  function createProposal(username, amount, description, url, details={}) {
+  function createContribution(username, amount, description, url, details={}) {
     return getContributorByWikiUser(username).then(contributor => {
-      robot.logger.debug(`[hubot-kredits] Creating proposal to issue ${amount}₭S to ${contributor.name} for ${url}...`);
+      robot.logger.debug(`[hubot-kredits] Creating contribution token for ${amount}₭S to ${contributor.name} for ${url}...`);
 
       let contribution = {
         contributorId: contributor.id,
@@ -44,8 +47,8 @@ module.exports = async function(robot, kredits) {
         kind: 'docs'
       };
 
-      return Proposal.addProposal(contribution).catch(error => {
-        robot.logger.error(`[hubot-kredits] Adding proposal failed:`, error);
+      return Contribution.addContribution(contribution).catch(error => {
+        robot.logger.error(`[hubot-kredits] Adding contribution failed:`, error);
       });
     }).catch(() => {
         robot.logger.info(`[hubot-kredits] No contributor found for ${username}`);
@@ -107,14 +110,15 @@ module.exports = async function(robot, kredits) {
     return results;
   }
 
-  function createProposals (changes) {
+  async function createContributions (changes) {
     let promises = [];
 
-    Object.keys(changes).forEach(user => {
-      promises.push(createProposalForUserChanges(user, changes[user]));
-    });
+    for (const user of Object.keys(changes)) {
+      await createContributionForUserChanges(user, changes[user]);
+      await sleep(60000);
+    }
 
-    return Promise.all(promises);
+    return Promise.resolve();
   }
 
   function pageTitlesFromChanges(changes) {
@@ -136,7 +140,7 @@ module.exports = async function(robot, kredits) {
     return amount;
   }
 
-  function createProposalForUserChanges (user, changes) {
+  function createContributionForUserChanges (user, changes) {
     const details = analyzeUserChanges(user, changes);
     const amount = calculateAmountForChanges(details);
 
@@ -157,7 +161,7 @@ module.exports = async function(robot, kredits) {
       url = `${wikiURL}index.php?title=${rc.title}&diff=${rc.revid}&oldid=${rc.old_revid}`;
     }
 
-    return createProposal(user, amount, desc, url, details);
+    return createContribution(user, amount, desc, url, details);
   }
 
   function updateTimestampForNextFetch () {
@@ -168,7 +172,7 @@ module.exports = async function(robot, kredits) {
   function processWikiChangesSinceLastRun () {
     fetchChanges()
       .then(res => groupChangesByUser(res))
-      .then(res => createProposals(res))
+      .then(res => createContributions(res))
       .then(() => updateTimestampForNextFetch());
   }